1. Field of the Invention
The present invention relates to a freezing system having two vaporizers for a refrigerator, in particular to a freezing system having two vaporizers for a refrigerator which is capable of providing a coolant to a compressor after mixing the each coolant passed through a freezing chamber vaporizer and a chilling chamber vaporizer and heightening the pressure.
2. Description of the Prior Art
As depicted in FIG. 1, the conventional freezing system for a refrigerator comprises a compressor 1 for converting a coolant into high temperature and high pressure vapor state by compressing the coolant, a condenser 2 for condensing the high temperature and high pressure vapor state coolant passed through the compressor 1 into a high pressure liquid state and at the same time rising a temperature of the surrounding air by performing the heat-exchange with the surrounding air, an expanding unit 4 for decompressing the high pressure liquid state coolant passed through the condenser 2 in order to vaporize easily, and a vaporizer 5 for converting the coolant passed through the expanding unit 4 into a low temperature and low pressure vapor state and at the same time lowering the temperature of the surrounding air by performing the heat-exchange with the surrounding air.
The compressor 1 and condenser 2 are installed on a machine room (not shown) of the refrigerator, a radiating fan 3 for radiating the condenser 2 and a motor 7 for providing a power to the radiating fan 3 are installed on the side of the condenser 2
In addition, the vaporizer 5 is installed on the rear side of a freezing chamber 8 of the refrigerator, and provides the cooling air to the freezing chamber 8 and a chilling chamber 9, a freezing fan 6 for absorbing the heat of the vaporizer 5 and a motor 10 for providing the power to the freezing fan 6 are installed on the side of the vaporizer 5.
The operation and effect of the freezing system of the conventional refrigerator will now be described with reference to accompanying FIG. 2.
First, a low temperature and low pressure state coolant a is converted into a high temperature and high pressure vapor state coolant b by being compressed by the compressor 1, and is soaked into the condenser 2, the condenser 2 changes the high temperature and high pressure vapor state coolant b into high temperature and high pressure liquid state c or of by releasing the heat continually.
A certain part of the coolant condensed by the condenser 2 is expanded as isenthalpic by being decompressed while passing through the expanding unit 4, and is changed into a quarter-phase state d mixed with the liquid and gas
After that, the coolant soaked into the vaporizer 5 totally vaporizes, is changed into the low temperature and low pressure state a or ag, and cools the surroundings by taking the heat of the surroundings during the vaporization.
The air cooled by the vaporizer 5 flows into the freezing chamber 8 and chilling chamber 9 through a cooling air duct (not shown) and a flow regulator (not shown), accordingly the each temperature of the freezing chamber 8 and chilling chamber 9 is stably kept as xe2x88x9218xc2x0 C. and 4xc2x0 C.
However, the conventional freezing system of the refrigerator cools the freezing chamber and chilling chamber as different temperature with only one vaporizer installed on the rear side of the freezing chamber, accordingly the energy efficiency of the refrigerator lowers because compression work of the compressor increases by the increase of the pressure difference between the vaporizer and condenser by setting the evaporating pressure of the coolant in the vaporizer according to the saturation temperature of the freezing chamber lower than the temperature of the chilling chamber.
In addition, in the conventional freezing system of the refrigerator, while the air cooled by the vaporizer is separately provided to the freezing chamber and chilling chamber, the air of the freezing chamber and chilling chamber can be mixed each other, moisture and food odor of the chilling chamber can flow into the freezing chamber, accordingly amenity of the refrigerator lowers.
In addition, in the conventional freezing system of the refrigerator, because of the moisture flowed from the chilling chamber a frost layer is formed on the surface of the vaporizer having very low temperature, accordingly the heat transmission efficiency of the vaporizer lowers, and at the same time air volume passing through the vaporizer decreases.
In addition, in the conventional freezing system of the refrigerator, a defrost system using an electronic heater is required in order to remove the frost layer formed on the surface of the vaporizer, the electronic heater consumes about 5xcx9c10% of the total electric consumption, accordingly the system efficiency lowers.
In the meantime, in order to solve the above-mentioned problems, the freezing system having the two vaporizers is developed.
There are different types of the freezing system having the two vaporizer, among them a dual-loop cycle and a single-loop cycle can be represented.
The dual-loop cycle comprises independent two freezing cycles having each different vaporizing temperature, it is good for the energy efficiency because the compression work of the compressor decreases drastically by reducing the pressure difference of the condenser by generating the high evaporating pressure, but it has to use the two compressors and two vaporizers, accordingly its usefulness lowers due to the increase of the supplementary expense.
The single-loop cycle can be represented as a Lorentz-Meutzner cycle which uses one compressor and two vaporizers, it does not have the efficiency lowering problem due to the increase of the supplementary expense because only one vaporizer is additionally installed, however a mixed coolant is required for this type, accordingly the usable mixed coolant has to be developed first, and can be provided cheaply.
The object of the present invention is to provide a freezing system having two vaporizers for a refrigerator which is capable of maximizing the energy efficiency with minimum supplementary expense by constructing a single-loop cycle usable with a genuine coolant as well as a mixed coolant by providing a coolant to a compressor after mixing the coolant separately passed through a freezing chamber vaporizer and a chilling chamber vaporizer through an ejector and heightening the pressure.
In order to achieve the above-mentioned object, the present invention comprises a compressor for compressing the coolant, a condenser for condensing the coolant compressed at the compressor, an expanding mean for the freezing chamber for depressing the coolant condensed at the condenser as a second pressure, an expanding mean for the chilling chamber for depressing the coolant condensed at the condenser as a second pressure, a vaporizer for the freezing chamber for cooling the air to be provided to the freezing chamber as a first temperature by vaporizing the coolant expanded at the expanding mean for the freezing chamber, a vaporizer for the chilling chamber for cooling the air to be provided to the chilling chamber as a second temperature by vaporizing the coolant expanded at the expanding mean for the chilling chamber, and an ejector for providing the coolant to the compressor after mixing the coolant passed through the vaporizer for the freezing chamber and vaporizer for the chilling chamber and compressing it.